2nd Gen Non-Engine/Transmission Low Voltage! Check Gage light comes on

[txwingrider]

Need your help please. I was heading out of town this weekend and all of the sudden the "Check Gage" light comes on so I then noticed the battery voltage is at 8 volts. I cancelled the trip, got 5th wheel trailer home and after going to auto store I was told it looked like the alternator was bad as it was only showing 66 amps. ( not real sure that they knew what they were doing) After searching I finally found a replacement alt. installed it and the gage light came on again with same as before readings.

Couple of items I need to mention... ... when I first start the truck, the battery gage reads around the 11 volt mark. After driving it for around 1-2 minutes, the bell goes off, the "check gage" light comes on and the battery voltage drops immediately to 8 volts! In the Service manual page 8J 33( I try to keep it short) it says," each time the cluster receives a message from the PCM indicating a charge fail condition(system voltage is 10. 8 volts or lower), the gage needle is moved to the 8 volts graduation on the gage scale and the check gages indicator is illuminated. The gage needle remains at 8 volts until the cluster receives a message from the PCM indicating there is no charge fail condition ( system voltage is 10. 9 volts or higher but lower than 16. 7. )

If anyone can shed some light on this I would REALLY appreciate it! and also do you think this is something that is covered under the 7 year/ 100,000 mile warranty? Some truck information... ... : year 2002, 15,000 miles, All stock except for Edge EZ, 2500, 4x4. Thanks in advance for your help! Cliff

 

[Graphic man]

i would start by checking the batterys with a load test and put a meter on the batterys and see if you have around 14. 5V with it running and about 12. 5 with it off, i would also check the grounds on the batterys and any other grounds you can find.



let us know what you find



Scott

 

[DavidC]

Maybe the sensor under the drivers side battery. Could be shorted as it is suppose to detect the battery temp and reduce charging voltage. There is a spec in the manual on what the ohm value of the sensor is suppose to be. I believe it has been posted somewhere here also.



Dave

 

[DavidC]

Found the link for ohm reading

http://turbodieselregister.com/forums/showthread.php?t=143884&highlight=battery+sensor



Dave

 

[txwingrider]

1st... ... ... . THANKS for the replys. Additional information... ... . as I look at both batteries (stock) I noticed that BOTH do not show any color in the small test indicator window ( no red, no green, nothing) I find this odd as it's both batteries ... . not just one NOTE:with leads disconnected it reads 10. 5 volts

DavidC - I will locate the sensor tomorrow to see if that reads correctly. ?? WITH motor running or not??

Graphic man -- Do I need to take my truck to a battery shop so that the load can be checked or is this something that I can do? and How?



Thanks guys!

 

[DBraunig]

Check the 140 amp fuse in the power distribution center. seen it blown lots of times.



Dave

 

[Graphic man]

you need a load tester to test the batterys, your local shop should have one.



Scott

 

[DavidC]

Sensor is checked disconnected from harness,engine not running. Meter set on ohms. You may not have a battery indicator window because of the discharge. It is probably a good idea to load check the batteries.



Dave

 

[txwingrider]

DBraunig-----I just took the 140 amp out and did a visual and continuity test and ... it's fine. Thanks for your reply -- Good idea anyway and I'm learning new stuff at the same time. I will go have the batteries load tested tomorow and let you know what I find out. Cliff

 

[txwingrider]

Update on the low voltage reading... ... ... ... ... ... .

I gave into making an appointment for tomorrow with the local Dodge dealer here in Colorado Springs to figure out what the heck was wrong with my truck. Before coming home this evening from work I went by a small auto repair shop that works on diesels and with in a few minutes the mechanic came back to tell me that the alternator was only putting out 33 amps! I told him about me installing a new one ( reconditioned) on Saturday and his first question was," how much did you pay for it?" I told him $144 and he said that was the problem as the cheaper ones just don't have what it takes to charge the system. Anyway, after trying several places to locate one he was told by the Dodge Dealer that there was one( brand new ) in Denver for $300. It will be here tomorrow so I will let you all know the results of the "new" alternator I'm hoping that this will fix it as I need to head out of town this coming weekend. If it does work I do plan to ask more questions about the difference between the knock off alternator and a factory one. I'll keep you all informed as to the results as you have helped me with some great ideas. Cliff

 

[wildmanben]

what became of this? Did you figure it out? My buddies truck is doing the same thing...

 

[ScottLewis]

FWIW, my '98 started doing the very same thing, especially if it had set a few days without running. It still started fine. I began panicking about all the things that could be wrong. Then, because they were the original batteries with about 90K miles and over 7 years on them, I decided to spring for WallyWorld's best.



BINGO! Problem resolved.



With your replacement alternator, you very well may have hit on the problem but, as many others have said, don't overlook the obvious. If you have low voltage, the source of the voltage may be weak. Test them out or, if they're old, replace them.





Dan

 

[Hitec.Redneck]

i had the same problem happen to me and it was the batteries. Replaced both batteries and problem was resolved.

 

[Sageair]

I agree about the cheap alternators not being worth the powder to blow em to hell. Lost the factory alt on my 03 Ford work truck. Replaced it twice with rebuilt units. Both failed almost immediately, put a original on and no problems now for 50,000 miles.